Devices may be used, for example, in the form of individual valves or as valve combinations in the inlet region of tanks or tank systems of motor vehicles in order to prevent overfilling of the pressure accumulator vessel with fuel during a replenishing or filling operation.
A shut-off valve for a pressure accumulator vessel for a medium, that includes a valve housing has a valve chamber with an intake opening and an outlet opening facing the pressure accumulator vessel, a movable piston, and at least one spring, is known from U.S. Pat. No. 3,709,241. In the case of this valve, a piston is guided in a bore of a valve body in order to limit the filling pressure in a tank. The piston has an elastic sealing element and is pressed against a constricted inlet opening by a spring. Between the bore of the valve body and the piston there is a gap through which gas may pass from the outlet region of the valve into a region of the bore behind the piston, and therefore, the pressure in the outlet region exerts an axial force on the piston, and thus, supports the spring in the closing of the inlet opening. Gas is thus prevented from flowing from the outlet region back to the inlet opening and at the same time the filling pressure is prevented from exceeding a predetermined value.
In addition, it is known that a filling pressure of a pressure accumulator vessel or a pressure accumulator system may be controlled and limited by measuring the pressure and by electronic control of electric valves.
In the applications mentioned, it is desirable for a permissible operating pressure of a pressure accumulator vessel or a pressure accumulator system to be reliably maintained during a filling operation and thus to ensure the maximum operating safety. The filling operation is intended to be able to be carried out as rapidly as possible and with only low energy losses. Wear to valve components is intended to be kept low and damage to pressure accumulator vessels and pressure lines is intended to be prevented.